memcheck/tests/err_disable3.c

   1
   2 /* Check that a child thread doesn't inherit its parent's disablement
   3    status. */
   4
   5 #include <stdlib.h>
   6 #include <stdio.h>
   7 #include <assert.h>
   8 #include <pthread.h>
   9 #include <unistd.h>    // sleep
  10
  11 #include "../include/valgrind.h"
  12
  13 char* block = NULL;
  14
  15 __attribute__((noinline)) void usechar ( char c )
  16 {
  17    // Spook gcc into believing mysterious bad things are
  18    // happening behind its back, and that 'c' is definitely
  19    // used in some (unknown) way.
  20    __asm__ __volatile__("" : : "r"(c) : "memory","cc");
  21 }
  22
  23 __attribute__((noinline)) void err ( void )
  24 {
  25    usechar( block[5] );
  26 }
  27
  28 void* child_fn ( void* arg )
  29 {
  30    fprintf(stderr, "\n--------- c: start (expect 1) ---------\n\n");
  31    err();
  32    fprintf(stderr, "\n--------- c: end ---------\n\n");
  33    return NULL;
  34 }
  35
  36 int main ( void )
  37 {
  38   int r;
  39   pthread_t child;
  40
  41   block = malloc(10);
  42   free(block);
  43
  44   fprintf(stderr, "\n--------- p: disabling errors (expect 0) ---------\n\n");
  45
  46   VALGRIND_DISABLE_ERROR_REPORTING;
  47   err();
  48
  49   fprintf(stderr, "\n--------- p: creating child ---------\n\n");
  50
  51   r = pthread_create(&child, NULL, child_fn, NULL);
  52   assert(!r);
  53   sleep(1); // let the child run first (determinism fix)
  54   fprintf(stderr, "\n--------- p: join child ---------\n\n");
  55   r = pthread_join(child, NULL);
  56   assert(!r);
  57
  58   fprintf(stderr, "\n--------- p: re_enabled (expect 1) ---------\n\n");
  59   VALGRIND_ENABLE_ERROR_REPORTING;
  60   err();
  61
  62   return 0;
  63 }